A print media product having magnetic receptive properties is typically prepared by applying a magnetic receptive coating to one-sided of a commercially extruded film after the extrusion process. This process, however, can only produce a product of one-sided printable surface. Retail graphics are always changing and the need for a product of double-sided printable surfaces is very real. Having the ability to reduce waste, lower shipping costs and mediate the need for installation is a game changer in the industry. Therefore, there exist a need for a simple process for producing a print media with magnetic receptive properties and a need for producing such print media with more than one-sided printable surface.
The processes of producing extruded single or multi-layer films are well known in the art. Commonly used processes include tubular blown film coextrusion, cast coextrusion, and water quench extrusion processes.
In many disclosed processes, numerous additions of both organic and inorganic media have been included in the master batch of polymers for extruded films. These have many commercial uses such as light blocking, increasing opacity and changing the post processing characteristics along with multiple other advantages. These additive approaches have been employed in the full range of media such as polypropylene, polyester, polyethylene and many other type and variations of synthetic films.
U.S. Pat. No. 5,945,205 discloses the use of fillers in the core layer (1st layer) for a light absorbing purpose to prevent spoilage of film-packaged food from UV degradation. In their process, they employ lamellar pigments such as graphite to enhance the voiding process and create an ultraviolet light block. This pigment is typically present in a 0.5% to 5% weight ratio. U.S. Pat. No. 4,345,005 discloses the use of additives to enhance adhesion of metalized coatings. Electron beam curing in a reactive setting, cures these coatings. This process is incapable of adding material that a magnet will adhere to. U.S. Pat. No. 4,117,193, teaches, that the inclusion of low-crystalline resin of an ethylene-butene copolymer and a polyolefin resin with a lubricant and an anti-blocking agent onto the surface produces a film that demonstrates low static properties and will aid in the prevention of blocking.
We have developed numerous magnetic receptive products from paints to papers and coated films. This product line allows us to produce a magnetic receptive print media in one co-extrusion process instead of a two-step process (which requires extruding a film followed by coating the film with a magnetic receptive media). In one aspect, this invention incorporates magnetic receptive particles into the formulation of a standard extruded film or a cast film so that the extruded film will adhere to magnets. In another aspect, the invention produce a print media in the form of a multilayered film comprising a magnetic receptive core layer for maintaining magnetic receptive properties, and one or more plastic layers attached to either one or both sides of the core layer, wherein the outermost surface(s) of the film is absent or substantially absent of ferromagnetic material and suitable to accept printing. The multilayered print film is conveniently produced by a co-extrusion technique.